Explicit type annotation in Swift - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a variable with an explicit type annotation.

Swift

var age: [1] = 25

Drag options to blanks, or click blank then click option'

AString

BBool

CInt

DDouble

Attempts:

3 left

💡 Hint

Common Mistakes

Using String instead of Int for numbers.

Forgetting to specify the type after the colon.

The variable age is declared with the explicit type Int to hold integer values.

2fill in blank

medium

Complete the code to declare a constant with an explicit type annotation.

Swift

let pi: [1] = 3.14159

Drag options to blanks, or click blank then click option'

ADouble

BInt

CBool

DString

Attempts:

3 left

💡 Hint

Common Mistakes

Using Int for decimal numbers causes errors.

Using String instead of a numeric type.

The constant pi is declared as a Double because it holds a decimal number.

3fill in blank

hard

Fix the error in the code by adding the correct explicit type annotation.

Swift

var isActive: [1] = true

Drag options to blanks, or click blank then click option'

ABool

BString

CInt

DDouble

Attempts:

3 left

💡 Hint

Common Mistakes

Using Int or String for boolean values.

Omitting the type annotation when it is required.

The variable isActive holds a true/false value, so it must be of type Bool.

4fill in blank

hard

Fill both blanks to declare a variable with explicit type annotation and assign a string value.

Swift

var name: [1] = [2]

Drag options to blanks, or click blank then click option'

AString

B"John"

CInt

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Using Int as the type for text.

Assigning a boolean value instead of a string.

The variable name is declared as a String and assigned the string value "John".

5fill in blank

hard

Fill all three blanks to declare a constant with explicit type annotation and assign a boolean value.

Swift

let isEnabled: [1] = [2] // [3]

Drag options to blanks, or click blank then click option'

AInt

BBool

Ctrue

DThis declares a boolean constant

Attempts:

3 left

💡 Hint

Common Mistakes

Using Int as the type for boolean values.

Putting the boolean value in quotes making it a string.

The constant isEnabled is declared as a Bool and assigned the boolean value true. The comment explains the declaration.